perf evlist: Make uniquifying counter names consistent

'perf stat' has different uniquification logic to 'perf record' and perf
top. In the case of perf record and 'perf top' all hybrid event names
are uniquified.

'perf stat' is more disciplined respecting name config terms, libpfm4
events, etc.

'perf stat' will uniquify hybrid events and the non-core PMU cases
shouldn't apply to perf record or 'perf top'.

For consistency, remove the uniquification for 'perf record' and 'perf
top' and reuse the 'perf stat' uniquification, making the code more
globally visible for this.

Fix the detection of cross-PMU for disabling uniquify by correctly
setting last_pmu.

When setting uniquify on an evsel, make sure the PMUs between the 2
considered events differ otherwise the uniquify isn't adding value.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Chun-Tse Shao <ctshao@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Levi Yun <yeoreum.yun@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Weilin Wang <weilin.wang@intel.com>
Link: https://lore.kernel.org/r/20250513215401.2315949-2-ctshao@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 148 deletions

diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
index e31d9f64d3ae..c022afb28514 100644
--- a/tools/perf/util/stat-display.c
+++ b/tools/perf/util/stat-display.c
@@ -915,61 +915,6 @@ static void printout(struct perf_stat_config *config, struct outstate *os,
 	}
 }
 
-static void evsel__uniquify_counter(struct evsel *counter)
-{
-	const char *name, *pmu_name;
-	char *new_name, *config;
-	int ret;
-
-	/* No uniquification necessary. */
-	if (!counter->needs_uniquify)
-		return;
-
-	/* The evsel was already uniquified. */
-	if (counter->uniquified_name)
-		return;
-
-	/* Avoid checking to uniquify twice. */
-	counter->uniquified_name = true;
-
-	name = evsel__name(counter);
-	pmu_name = counter->pmu->name;
-	/* Already prefixed by the PMU name. */
-	if (!strncmp(name, pmu_name, strlen(pmu_name)))
-		return;
-
-	config = strchr(name, '/');
-	if (config) {
-		int len = config - name;
-
-		if (config[1] == '/') {
-			/* case: event// */
-			ret = asprintf(&new_name, "%s/%.*s/%s", pmu_name, len, name, config + 2);
-		} else {
-			/* case: event/.../ */
-			ret = asprintf(&new_name, "%s/%.*s,%s", pmu_name, len, name, config + 1);
-		}
-	} else {
-		config = strchr(name, ':');
-		if (config) {
-			/* case: event:.. */
-			int len = config - name;
-
-			ret = asprintf(&new_name, "%s/%.*s/%s", pmu_name, len, name, config + 1);
-		} else {
-			/* case: event */
-			ret = asprintf(&new_name, "%s/%s/", pmu_name, name);
-		}
-	}
-	if (ret > 0) {
-		free(counter->name);
-		counter->name = new_name;
-	} else {
-		/* ENOMEM from asprintf. */
-		counter->uniquified_name = false;
-	}
-}
-
 /**
  * should_skip_zero_count() - Check if the event should print 0 values.
  * @config: The perf stat configuration (including aggregation mode).
@@ -1060,8 +1005,6 @@ static void print_counter_aggrdata(struct perf_stat_config *config,
 	if (counter->merged_stat)
 		return;
 
-	evsel__uniquify_counter(counter);
-
 	val = aggr->counts.val;
 	ena = aggr->counts.ena;
 	run = aggr->counts.run;
@@ -1636,96 +1579,6 @@ static void print_cgroup_counter(struct perf_stat_config *config, struct evlist
 		print_metric_end(config, os);
 }
 
-/* Should uniquify be disabled for the evlist? */
-static bool evlist__disable_uniquify(const struct evlist *evlist)
-{
-	struct evsel *counter;
-	struct perf_pmu *last_pmu = NULL;
-	bool first = true;
-
-	evlist__for_each_entry(evlist, counter) {
-		/* If PMUs vary then uniquify can be useful. */
-		if (!first && counter->pmu != last_pmu)
-			return false;
-		first = false;
-		if (counter->pmu) {
-			/* Allow uniquify for uncore PMUs. */
-			if (!counter->pmu->is_core)
-				return false;
-			/* Keep hybrid event names uniquified for clarity. */
-			if (perf_pmus__num_core_pmus() > 1)
-				return false;
-		}
-	}
-	return true;
-}
-
-static void evsel__set_needs_uniquify(struct evsel *counter, const struct perf_stat_config *config)
-{
-	struct evsel *evsel;
-
-	if (counter->merged_stat) {
-		/* Counter won't be shown. */
-		return;
-	}
-
-	if (counter->use_config_name || counter->is_libpfm_event) {
-		/* Original name will be used. */
-		return;
-	}
-
-	if (!config->hybrid_merge && evsel__is_hybrid(counter)) {
-		/* Unique hybrid counters necessary. */
-		counter->needs_uniquify = true;
-		return;
-	}
-
-	if  (counter->core.attr.type < PERF_TYPE_MAX && counter->core.attr.type != PERF_TYPE_RAW) {
-		/* Legacy event, don't uniquify. */
-		return;
-	}
-
-	if (counter->pmu && counter->pmu->is_core &&
-	    counter->alternate_hw_config != PERF_COUNT_HW_MAX) {
-		/* A sysfs or json event replacing a legacy event, don't uniquify. */
-		return;
-	}
-
-	if (config->aggr_mode == AGGR_NONE) {
-		/* Always unique with no aggregation. */
-		counter->needs_uniquify = true;
-		return;
-	}
-
-	/*
-	 * Do other non-merged events in the evlist have the same name? If so
-	 * uniquify is necessary.
-	 */
-	evlist__for_each_entry(counter->evlist, evsel) {
-		if (evsel == counter || evsel->merged_stat)
-			continue;
-
-		if (evsel__name_is(counter, evsel__name(evsel))) {
-			counter->needs_uniquify = true;
-			return;
-		}
-	}
-}
-
-static void evlist__set_needs_uniquify(struct evlist *evlist, const struct perf_stat_config *config)
-{
-	struct evsel *counter;
-
-	if (evlist__disable_uniquify(evlist)) {
-		evlist__for_each_entry(evlist, counter)
-			counter->uniquified_name = true;
-		return;
-	}
-
-	evlist__for_each_entry(evlist, counter)
-		evsel__set_needs_uniquify(counter, config);
-}
-
 void evlist__print_counters(struct evlist *evlist, struct perf_stat_config *config,
 			    struct target *_target, struct timespec *ts,
 			    int argc, const char **argv)
@@ -1737,7 +1590,7 @@ void evlist__print_counters(struct evlist *evlist, struct perf_stat_config *conf
 		.first = true,
 	};
 
-	evlist__set_needs_uniquify(evlist, config);
+	evlist__uniquify_evsel_names(evlist, config);
 
 	if (config->iostat_run)
 		evlist->selected = evlist__first(evlist);